[Reflection] Add support for imported structs with recorded fields (attempt #2)

include/swift/Reflection/Records.h

@@ -186,6 +186,10 @@ class FieldDescriptor {
             Kind == FieldDescriptorKind::ObjCProtocol);
   }
 
+  bool isStruct() const {
+    return Kind == FieldDescriptorKind::Struct;
+  }
+
   const_iterator begin() const {
     auto Begin = getFieldRecordBuffer();
     auto End = Begin + NumFields;

lib/IRGen/GenMeta.cpp

@@ -5618,7 +5618,9 @@ IRGenModule::getAddrOfForeignTypeMetadataCandidate(CanType type) {
   } else if (auto structType = dyn_cast<StructType>(type)) {
     auto structDecl = structType->getDecl();
     assert(isa<ClangModuleUnit>(structDecl->getModuleScopeContext()));
-
+
+    ImportedStructs.insert(structDecl);
+
     ForeignStructMetadataBuilder builder(*this, structDecl, init);
     builder.layout();
     addressPoint = builder.getOffsetOfAddressPoint();

lib/IRGen/GenReflection.cpp

@@ -368,12 +368,13 @@ class FieldTypeMetadataBuilder : public ReflectionMetadataBuilder {
     B.addInt16(fieldRecordSize);
 
     // Imported classes don't need field descriptors
-    if (NTD->hasClangNode()) {
-      assert(isa<ClassDecl>(NTD));
+    if (NTD->hasClangNode() && isa<ClassDecl>(NTD)) {
       B.addInt32(0);
       return;
     }
 
+    assert(!NTD->hasClangNode() || isa<StructDecl>(NTD));
+
     auto properties = NTD->getStoredProperties();
     B.addInt32(std::distance(properties.begin(), properties.end()));
     for (auto property : properties)
@@ -435,6 +436,7 @@ class FieldTypeMetadataBuilder : public ReflectionMetadataBuilder {
   void layout() override {
     if (NTD->hasClangNode() &&
         !isa<ClassDecl>(NTD) &&
+        !isa<StructDecl>(NTD) &&
         !isa<ProtocolDecl>(NTD))
       return;
 
@@ -941,6 +943,9 @@ void IRGenModule::emitBuiltinReflectionMetadata() {
   for (auto PD : ImportedProtocols)
     emitFieldMetadataRecord(PD);
 
+  for (auto SD : ImportedStructs)
+    emitFieldMetadataRecord(SD);
+
   for (auto builtinType : BuiltinTypes)
     emitBuiltinTypeMetadataRecord(builtinType);
 

lib/IRGen/IRGenModule.h

@@ -920,6 +920,9 @@ class IRGenModule {
   /// Imported protocols referenced by types in this module when emitting
   /// reflection metadata.
   llvm::SetVector<const ProtocolDecl *> ImportedProtocols;
+  /// Imported structs referenced by types in this module when emitting
+  /// reflection metadata.
+  llvm::SetVector<const StructDecl *> ImportedStructs;
 
   llvm::Constant *getAddrOfStringForTypeRef(StringRef Str);
   llvm::Constant *getAddrOfFieldName(StringRef Name);

stdlib/public/Reflection/TypeLowering.cpp

@@ -1057,16 +1057,18 @@ class LowerType
 
   const TypeInfo *visitAnyNominalTypeRef(const TypeRef *TR) {
     const auto &FD = TC.getBuilder().getFieldTypeInfo(TR);
-    if (FD.first == nullptr) {
+    if (FD.first == nullptr || FD.first->isStruct()) {
       // Maybe this type is opaque -- look for a builtin
       // descriptor to see if we at least know its size
       // and alignment.
       if (auto ImportedTypeDescriptor = TC.getBuilder().getBuiltinTypeInfo(TR))
         return TC.makeTypeInfo<BuiltinTypeInfo>(ImportedTypeDescriptor);
 
       // Otherwise, we're out of luck.
-      DEBUG(std::cerr << "No TypeInfo for nominal type: "; TR->dump());
-      return nullptr;
+      if (FD.first == nullptr) {
+        DEBUG(std::cerr << "No TypeInfo for nominal type: "; TR->dump());
+        return nullptr;
+      }
     }
 
     switch (FD.first->Kind) {

test/Reflection/typeref_decoding_imported.swift

@@ -20,6 +20,19 @@
 // CHECK-32: mce: __C.MyCEnum
 // CHECK-32: (struct __C.MyCEnum)
 
+// CHECK-32: __C.MyCStruct
+// CHECK-32: -------------
+// CHECK-32: i: Swift.Int32
+// CHECK-32: (struct Swift.Int32)
+
+// CHECK-32: ip: Swift.Optional<Swift.UnsafeMutablePointer<Swift.Int32>>
+// CHECK-32: (bound_generic_enum Swift.Optional
+// CHECK-32:   (bound_generic_struct Swift.UnsafeMutablePointer
+// CHECK-32:     (struct Swift.Int32)))
+
+// CHECK-32: c: Swift.Int8
+// CHECK-32: (struct Swift.Int8)
+
 // CHECK-32: TypesToReflect.AlsoHasCTypes
 // CHECK-32: ----------------------------
 
@@ -82,6 +95,19 @@
 // CHECK-64: mcu: __C.MyCUnion
 // CHECK-64: (struct __C.MyCUnion)
 
+// CHECK-64: __C.MyCStruct
+// CHECK-64: -------------
+// CHECK-64: i: Swift.Int32
+// CHECK-64: (struct Swift.Int32)
+
+// CHECK-64: ip: Swift.Optional<Swift.UnsafeMutablePointer<Swift.Int32>>
+// CHECK-64: (bound_generic_enum Swift.Optional
+// CHECK-64:   (bound_generic_struct Swift.UnsafeMutablePointer
+// CHECK-64:     (struct Swift.Int32)))
+
+// CHECK-64: c: Swift.Int8
+// CHECK-64: (struct Swift.Int8)
+
 // CHECK-64: TypesToReflect.AlsoHasCTypes
 // CHECK-64: ----------------------------